求20道方程题,和简便算法计算小数,分数.

求20道方程题,和简便算法计算小数,分数.
下册的

31×43－31＋58×31 56×78＋13×83＋27×78＋83×9
199 + 99×99 7.63×9.9＋0.763
3.74×5.8＋62.6×0.58 3.43×14＋1.4×75.7－14
1.120-36×4÷18+35
2.（58+37）÷（64-9×5）
3.(6.8-6.8×0.55)÷8.5
4.0.12× 4.8÷0.12×4.8
5.（3.2×1.5+2.5）÷1.6 （2）3.2×（1.5+2.5）÷1.6
6.6-1.6÷4= 5.38+7.85-5.37=
7.7.2÷0.8-1.2×5= 6-1.19×3-0.43=
8.6.5×（4.8-1.2×4）= 0.68×1.9+0.32×1.9
9.10.15-10.75×0.4-5.7
10.5.8×（3.87-0.13）+4.2×3.74
11.32.52-（6+9.728÷3.2）×2.5
12.6 ×（ 1/2 + 2/3 ）
13.8 × 4/5 + 8 × 11/5
14.31 × 5/6 – 5/6
15.9/7 - （ 2/7 – 10/21 ）
16.5/9 × 18 – 14 × 2/7
17.4/5 × 25/16 + 2/3 × 3/4
18.14 × 8/7 – 5/6 × 12/15
19.17/32 – 3/4 × 9/24
20.3 × 2/9 + 1/3
21.5/7 × 3/25 + 3/7
22.3/14 ×× 2/3 + 1/6
23.1/5 × 2/3 + 5/6
24.9/22 + 1/11 ÷ 1/2
25.5/3 × 11/5 + 4/3
26.45 × 2/3 + 1/3 × 15
27.7/19 + 12/19 × 5/6
28.1/4 + 3/4 ÷ 2/3
29.8/7 × 21/16 + 1/2
30.101 × 1/5 – 1/5 × 21
31.[-|98|+76+(-87)]*23[56+(-75)-(7)]-(8+4+3)
32.5+21*8/2-6-59
33.68/21-8-11*8+61
34.-2/9-7/9-56
35.4.6-(-3/4+1.6-4-3/4)
36.1/2+3+5/6-7/12
37.[2/3-4-1/4*(-0.4)]/1/3+2
38.22+(-4)+(-2)+4*3
39.-2*8-8*1/2+8/1/8
40.(2/3+1/2)/(-1/12)*(-12)
41.(-28)/(-6+4)+(-1)
42.2/(-2)+0/7-(-8)*(-2)
43.(1/4-5/6+1/3+2/3)/1/2
44.18-6/(-3)*(-2)
45.(5+3/8*8/30/(-2)-3
46.(-84)/2*(-3)/(-6)
47.1/2*(-4/15)/2/3
48.-3x+2y-5x-7y
49.2/3÷1/2－1/4×2/5
50.2－6/13÷9/26－2/3
解方程.
①12 －4x＝2
②38:x＝4.75:1
③1/3 x＋5/6 x＝1.4
12 x＋34 x=1
18x－14 x= 12
23 x－5×14 = 14
12 ＋34 x=56
22－14 x= 12
23 x－14 x= 14
x＋14 x= 65
23 x=14 x ＋14
30 x－12 x －14 x=12
20%+(1-20%)(320-x)=320×40%
2(x-2)+2=x+1
2(x-2)-3(4x-1)=9(1-x)
11x+64-2x=100-9x
15-(8-5x)=7x+(4-3x)
3(x-7)-2[9-4(2-x)]=22
3/2[2/3(1/4x-1)-2]-x=2